Question on a Rammus build

I remember playing against a player one time who was Rammus. Rather than going full tank or whatnot, he had Thornmail+Randuin Omen and then 3 attack items that have damage+attack speed. Now, this build easily took down any single target but was ultimately useless during the team fights. But the damage output was insane as he'd take down any champ before the taunt finished.

Is this a viable build if you can use it and end a match before late game?---I <3 Joel "Alien" Anthony's head.

I mean if it worked I can't really fault him for it. It's like going for 2 points in football if it works you're a hero if it doesn't you're reported for feeding.---Steam ID: Brutal_FelixIntel Core i5 3570k 4.4Ghz | ASRock Z77 Extreme4 | Ripjaws X Series 8 GB | Samsung 840 Pro Series 256 GB | Gigabyte Radeon HD 7970